Lateral Compartment Research Articles

Predictive Factors for Lateral Hinge Fracture in Medial Closing Wedge Distal Femoral Osteotomy

Background: Recent studies have reported that lateral hinge fracture (LHF) has a negative effect on bone healing at the osteotomy site after medial closing wedge distal femoral osteotomy (MCDFO). However, limited evidence exists in the literature regarding the predictive factors for LHF in MCDFO. Hypothesis: A large medial closing gap and a lateral hinge position in the supracondylar area would increase plain radiography–based and/or computed tomography (CT)–based LHF in MCDFO. Study Design: Case control study; Level of evidence, 3. Methods: We retrospectively evaluated 67 knees of 53 patients (mean age, 37.4 ± 16.9 years) who underwent MCDFO between May 2009 and June 2021. The surgical indications for MCDFO were genu valgum deformity combined with either lateral compartment osteoarthritis or recurrent patellar dislocation. The presence of LHF was evaluated based on immediate postoperative plain radiography and CT scans. The predictive factors for LHF in MCDFO were investigated using multivariate logistic regression analysis. Results: LHFs were identified in 21 knees (31.3%) through plain radiography and in 40 knees (59.7%) through CT. Multivariate logistic regression analysis showed that the medial closing gap and lateral hinge position were predictive factors for plain radiography– and CT-based LHF after MCDFO. Controlling for other variables, we found that an increase in the medial opening gap by 1 mm increased the likelihood of plain radiography–based LHF by a factor of 1.805 (95% CI, 1.291-2.525; P = .001) and CT-based LHF by 1.333 (95% CI, 1.003-1.772; P = .048). Moreover, a lateral hinge position in the supracondylar area increased the likelihood of plain radiography–based LHF by a factor of 9.870 (95% CI, 2.179-44.720; P = .003) and CT-based LHF by 5.686 (95% CI, 1.124-28.754; P = .036). Conclusion: A large medial closing gap and lateral hinge position in the supracondylar area are associated with LHF in MCDFO. Care should be taken to prevent LHF in MCDFO with a large medial closing gap. Moreover, a lateral hinge position in the supracondylar area should be avoided to decrease the incidence of LHF in MCDFO.

Completion thyroidectomy and lateral neck dissection revealed adhesions in the lateral neck compartment after gasless transaxillary endoscopic thyroidectomy: a case report

Endoscopic thyroidectomy is effective and safe surgical option for thyroid surgery while providing satisfactory cosmetic results. Gasless transaxillary endoscopic approaches have been reported to achieve endoscopic thyroidectomy in our center. We present a patient who previously underwent gasless transaxillary endoscopic lobectomy with ipsilateral central neck dissection who underwent open completion thyroidectomy and lateral neck dissection (LND) (reoperation) in our center. The ultrasound test before the first treatment did not reveal abnormal lymph nodes in the central and lateral neck compartments. Further evaluation of the neck lymph nodes was not performed. Meanwhile, this patient did not participate in the originally planned follow-up at the 3- and 6-month visits. At the one-year visit, imaging tests revealed enlarged and suspicious malignant lymph nodes in levels III and IV of the lateral neck compartments. We believed that reoperation was performed for persistent, rather than truly recurrent disease for this patient. During the second surgery, we found that the surface of internal jugular vein (IJV) was significantly adhered to the surrounding fibroadipose tissue and the omohyoid muscle was adhered to the IJV. After carefully dissected the IJV, the dissection of the lateral neck compartment had been performed successfully. Exposure of the lateral neck compartment in the gasless transaxillary procedure, especially exposure of the IJV, causes adhesions of the lateral neck compartment and brings difficulties for possible future LND. Gasless transaxillary endoscopic thyroid surgery should be performed in strictly selected patients with adequate preoperative assessment. The IJV should be carefully dissected to avoid IJV injury, and the lateral neck compartment could be dissected successfully during reoperation.

Treatment of Knee Dislocation With Primary Repair and Suture Augmentation: A Viable Solution.

Different surgical techniques have been described for the treatment of knee dislocation (KD). Nonoperative approaches are frequently combined with surgical reconstruction using auto- or allograft. To evaluate the midterm results of primary surgical repair and suture augmentation to treat KD. Case series; Level of evidence, 4. A total of 22 patients (5 women, 17 men; mean age, 45 ± 15 years) with KD were evaluated at a mean of 49 ± 16 months after surgical treatment that included primary repair and suture augmentation. Magnetic resonance imaging, stress radiographs, and outcome scores were obtained at the follow-up. Clinical examination including hop tests and force measurements for flexion and extension was performed. The mean difference in pre- to postinjury Tegner scores was -2 ± 1. The outcome scores showed mean values of 84 ± 15 (Lysholm), 73 ± 15 (International Knee Documentation Committee) and 65 ± 25 (Anterior Cruciate Ligament-Return to Sport after Injury scale). Compared with the uninjured knee, the range of motion of the injured knee was reduced by 21° ± 12°. Twelve patients felt fit enough to perform hop tests and showed a mean deficit of 7% ± 17%° compared with the uninjured leg. The mean force deficit was 19% ± 18% for extension and 8% ± 16% for flexion. Stress radiographs revealed an 11 ± 7-mm higher anteroposterior translation on the injured side. Four patients had secondary ligament reconstructions due to persistent instability and 7 underwent arthroscopic arthrolysis due to stiffness. A significant increase of osteoarthritis was found for the medial, lateral, and patellofemoral compartments (P = .007, .004, and .006, respectively). Primary repair and suture augmentation of KD led to satisfactory clinical midterm results despite persistent radiological instability and a significant increase in osteoarthritis. This technique allows the return to activities of daily living without subjective instability in most nonathletic patients. Secondary ligament reconstructions should be performed if relevant instability persists to decrease the risk of secondary meniscal and cartilage damage.

Endoscopic lateral neck dissection via the breast and transoral approaches for papillary thyroid carcinoma: A preliminary report

Complete lymph node dissection is essential for the management of papillary thyroid carcinoma (PTC) with lymph node metastasis (LNM). This work aimed to describe the feasibility of endoscopic lateral neck dissection via the breast and transoral approach (ELNDBTOA) in PTC patients and the necessity of the addition of the transoral approach. We included 13 patients with PTC and suspected lateral LNM who underwent ELNDBTOA at the Zhongshan Hospital, Xiamen University. Total thyroidectomy, ipsilateral central lymph node dissection, and selective neck dissection (levels IIA, IIB, III, and IV) were performed endoscopically via the breast approach. Residual lymph nodes were further dissected via the transoral approach. The mean operation time was 362.1 ± 73.5 min. In the lateral neck compartments, the mean number of retrieved lymph nodes was 36.6 ± 23.8, and the mean number of positive lymph nodes was 6.8 ± 4.7. In further dissection via the transoral approach, lymph nodes in the lateral neck compartment were obtained in nine patients (9/13, 69.2%), and three patients (3/13, 23.1%) had confirmed lateral neck metastases. Transient hypocalcemia occurred in two patients (2/13, 15.4%), and three patients (3/13, 23.1%) developed transient skin numbness in the mandibular area. No other major complications were observed. There was no evidence of local recurrence or distant metastasis during the follow-up period (range, 24-87 months). All patients were satisfied with the good cosmetic outcome. ELNDBTOA is an option with proven feasibility for select PTC patients with LNM, and the addition of the transoral approach is necessary to ensure complete dissection.

Repair of Acute Grade 3 Combined Posterolateral Corner Avulsion Injuries Using an Enhanced Fixation Technique.

Previous studies have suggested that surgical repair of the posterolateral corner (PLC) may be inferior to reconstruction. We hypothesized that acute repair (<3 weeks) of avulsion-type PLC multiligament knee injuries with no midsubstance injury would lead to lower failure rates than previously reported for PLC repair. Case series; Level of evidence, 4. A total of 28 patients with multiligament knee injuries who underwent acute repair between January 2007 and June 2018 of a PLC avulsion injury with no evidence of midsubstance tearing were included. All PLC avulsion injuries were treated using a transosseous Krackow suture pull-through technique without graft augmentation. Outcome metrics included lateral joint-space widening with varus stress, patient-reported clinical varus instability, patient-reported outcome measures (PROMs), and any subsequent revision or salvage procedure. The mean time from injury to repair was 8.1 ± 5 days. At a mean follow-up of 2 years (range, 3-90 months), clinical varus stress examination at 30° demonstrated a significant reduction in lateral compartment opening, from 9 ± 3 mm preoperatively to 0 ± 3 mm (P < .0001). The failure rate was calculated to be 10.7% (3/28), which was significantly lower than the failure rate from a 2016 systematic review (38%, 17/45; P = .015). Of the 28 patients, 21 (75%) had PROM scores. Patients who underwent staged bi-cruciate reconstructions (n = 5) had significantly higher subjective International Knee Documentation Committee (IKDC) (87.2 vs 65.5; P = .014) and Lysholm (90.5 vs 75.2; P = .029) scores compared to patients with untreated bi-cruciate injuries (n = 9). Patients with peroneal nerve injury (n = 4) had significantly lower IKDC (58.2 vs 80.8; P = .0045) and Tegner (3.2 vs 5.4; P = .047) scores than those without peroneal nerve injury (n = 17). The mean IKDC and Lysholm scores at final follow-up were 73.4 ± 24.0 and 80.8 ± 23.1 at 7.1 years (range, 2.3-10.6 years) of follow-up. Repair of acute grade 3 combined PLC avulsion injuries using a transosseous Krackow suture pull-through technique demonstrated a failure rate of 10.7%. Patients who underwent a staged cruciate reconstruction(s) had higher subjective outcome scores than those who had cruciate injuries left untreated. Peroneal nerve injury was associated with lower outcome scores.

Radial Head Stress Fracture Nonunion in Adolescent Overhead Athletes: A Case Series

Background: While osteochondritis dissecans of the humeral capitellum is well-described in adolescent overhead athletes, lateral compartment overload may also present with isolated radial head involvement. The primary goals of this study are to present a case series of radial head stress fracture nonunions in adolescent athletes and to provide guidelines regarding surgical indications and treatment. We hypothesize that surgical reduction and fixation of symptomatic lesions is safe, effective, and preserves the stability and articular congruity of the radiocapitellar joint.Methods: We retrospectively reviewed the clinical and radiographic records of nine patients presenting to a pediatric tertiary care center for radial head stress fracture nonunion from January 2008 to December 2016. Patient characteristics, presenting signs and symptoms, clinical and radiographic features, postoperative elbow motion, and radiographic healing were assessed.Results: Nine patients (five female; mean age 12.0 years [range 9.3-14.8 years] at time of injury) were treated for symptomatic radial head stress fracture nonunion. All patients reported persistent elbow pain with activities of daily living (ADLs) and athletics. Seven patients had limited elbow range of motion. Radiographically, the nonunion fragments comprised 20-45% of the radial head articular surface, and five patients had concomitant radial head subluxation. Five patients underwent open reduction internal fixation, one patient underwent microfracture and debridement, and one patient underwent intraarticular corrective osteotomy. All operative patients had improved or complete resolution of pain with ADLs. Additionally, all operative patients had either some increase in or complete regain of full elbow range of motion. Progressive or complete radiographic healing was seen at a median of 14 weeks postoperatively.Conclusions: In this case series, skeletally immature athletes with radial head stress fracture nonunions experienced pain relief, maintained or improved motion, and radiographic bony union following surgical intervention. Radiocapitellar joint stability and congruity were preserved or restored.Level of Evidence: Case series; Level IV Key Concepts•With increased participation in overhead and/or throwing sports, repetitive valgus stress on the elbow may lead to lateral compartment overload injuries.•While osteochondritis dissecans (OCD) of the capitellum is well-characterized, isolated radial head stress injuries may also occur.•Surgical treatment for symptomatic or displaced radial head stress injuries may provide pain relief, bony healing, improved range of motion, and return to sports.•Patients, families, and providers should be aware of this clinical condition, and surgical treatment should be considered in cases of persistent pain, bony nonunion, displacement, joint instability and/or incongruity.

Proximal fibular osteotomy versus high tibial osteotomy for treating knee osteoarthritis: a systematic review and meta-analysis

BackgroundKnee osteoarthritis (KOA) with varus alignment and medial space stenosis is a common degenerative disorder in the elderly. To reallocate the force bearing from the medial to the lateral compartment, the anti-varus osteotomy, including high tibial osteotomy (HTO) and proximal fibular osteotomy (PFO), corrects the mechanical lines of lower extremities using surgical methods, which alleviates the abrasion of medial cartilage and relieves pain. PFO is based on the “non-uniform settlement” theory. It is to cut small section of the proximal fibula, i.e., below the fibula head, which breaks the fibula and weakens its support for the lateral of the tibial plateau, lastly reduces the gap on the lateral side of the knee joint and offsets the knee varus deformity caused by weight bearing. We conducted this systematic review and meta-analysis to compare the clinical outcomes of PFO versus HTO intervention.MethodsTwenty-three studies were acquired from PubMed, Embase, CNKI (China National Knowledge Infrastructure), Wanfang Database and Cochrane Library. The data were extracted by two of the coauthors independently and were analyzed by RevMan5.3. Mean differences (MDs), odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration’s Risk of Bias Tool and Newcastle–Ottawa Scale were used to assess risk of bias.ResultsTwenty-three studies including 14 randomized controlled trials and 9 observational studies were assessed. The methodological quality of the trials ranged from low to high. The pooled results of the mean operation time (MD = − 38.75, 95% CI = − 45.66 to − 31.85, P < 0.00001), intraoperative bleeding (std. MD = − 4.12, 95% CI = − 5 to − 3.24, P < 0.00001), length of hospital stay (MD = − 3.77, 95% CI = − 4.98 to − 2.56, P < 0.00001) and postoperative complications (OR = 0.66, 95% CI = 0.37–1.18, P = 0.16) showed that the differences were statistically significant between the two interventions. The postoperative differences of visual analogue score (VAS) (MD = 0.15 95% CI = − 0.39 to 0.69, P = 0.58), hospital for Special Surgery knee score (HSS) (MD = − 2.68, 95% CI = − 6.30 to 0.94, P = 0.15), American knee society (AKS) score (MD = 0.04, 95% CI = − 0.69 to 0.77, P = 0.91), western Ontario and McMaster university of orthopedic index (WOMAC) (MD = 8.09, 95% CI = 2.06–14.13, P = 0.009) and femur–tibia angle (FTA) (MD = − 0.03, 95% CI = − 5.39 to 5.33, P = 0.99) were not statistically significant. Sensitivity analysis proved the stability of the pooled results and the publication bias was not apparent.ConclusionsPFO and HTO have the same short-term efficacy in the treatment of KOA, but PFO can reduce the operation time, intraoperative bleeding, hospital stay and postoperative complications, which has certain advantages. Clinically, for patients with many complications and poor surgical tolerance, PFO can be preferred.

An Automatic Method for Assessing Spiking of Tibial Tubercles Associated with Knee Osteoarthritis.

Efficient and scalable early diagnostic methods for knee osteoarthritis are desired due to the disease's prevalence. The current automatic methods for detecting osteoarthritis using plain radiographs struggle to identify the subjects with early-stage disease. Tibial spiking has been hypothesized as a feature of early knee osteoarthritis. Previous research has demonstrated an association between knee osteoarthritis and tibial spiking, but the connection to the early-stage disease has not been investigated. We study tibial spiking as a feature of early knee osteoarthritis. Additionally, we develop a deep learning based model for detecting tibial spiking from plain radiographs. We collected and graded 913 knee radiographs for tibial spiking. We conducted two experiments: experiments A and B. In experiment A, we compared the subjects with and without tibial spiking using Mann-Whitney U-test. Experiment B consisted of developing and validating an interpretative deep learning based method for predicting tibial spiking. The subjects with tibial spiking had more severe Kellgren-Lawrence grade, medial joint space narrowing, and osteophyte score in the lateral tibial compartment. The developed method achieved an accuracy of 0.869. We find tibial spiking a promising feature in knee osteoarthritis diagnosis. Furthermore, the detection can be automatized.

Thyroglobulin Levels as a Predictor of Papillary Cancer Recurrence After Thyroid Lobectomy.

The effectiveness of using serum thyroglobulin (TG) to predict thyroid cancer recurrence after a thyroid lobectomy is unknown. This study aimed to evaluate the predictive nature of serum TG and TG trends after thyroid lobectomies. We analyzed 514 papillary thyroid cancer (PTC) patients. The pre-, low-, high, and last-TG levels were reviewed and stratified into three groups. An ascending TG trend was defined if the last-TG level was more than 200% as high as the value of low-TG level. A descending trend was defined if the last-TG level decreased by more than 50% and a flat trend as between them. During a median follow-up period of 73.0 months, there were 21 (4.1%) recurrences. Most patients showed a descending (54.1%) or flat (35.6%) TG trend, but 10.3% of patients showed an ascending TG trend. Overall and lateral recurrences were significantly higher in the ascending TG group, indicating that an ascending TG trend was a good predictor for recurrence. Other factors such as positive node ratio (PNR), patient risk, age, and sex were not significant risk factors. In a Kaplan-Meier analysis, ascending TG trend was a good predictor of lateral recurrence. TG levels as a predictor of papillary cancer recurrence after thyroid lobectomy were found to be poor classifiers, and optimal cut-off values were not verified. An ascending TG trend was a good predictor of lateral recurrence. Further studies are warranted to investigate whether an ascending TG trend was due to an incomplete thyroid lobectomy or if the cancer had already metastasized to the lateral compartment.

Prospective sequential comparison of femoral roll-back between cruciate-retaining and posterior-stabilized total knee arthroplasty using an intra-operative sensor

BackgroundImplant design and surgical techniques affect postoperative knee kinematics in total knee arthroplasty (TKA). This study aimed to compare femoral roll-back between cruciate-retaining (CR) and posterior-stabilized (PS) TKA in the same knee by objectively quantifying the contact point kinematics of the tibiofemoral joint using a sensor. MethodsIn the present prospective study, we used an intraoperative sensor to compare medial and lateral roll-back during 0-120° knee flexion in 33 knees that underwent CR and PS TKA. We also examined the relationship between mediolateral balance and the lateral-to-medial roll-back ratio. We defined the contact percentage position as the vertical length to the contact point divided by the anteroposterior length of the tibial plate. ResultsThe roll-back percentage following PS TKA (19.8 ± 5.1%) was significantly higher than that after CR TKA in both the medial (19.8 ± 5.1% versus 7.1 ± 2.5%, P < 0.001) and lateral (26.8% ± 3.8% versus 18.7 ± 3.8%, P < 0.001) compartments. The medial contact pressure at 90° was significantly correlated with the increased lateral-to-medial roll-back ratio in both CR and PS TKA (both P < 0.001). ConclusionPS TKA resulted in a higher percentage of femoral roll-back in the medial and lateral compartments than CR TKA. CR TKA caused a higher lateral-to-medial roll-back ratio compared to PS TKA. To reproduce medial pivot knee motion similar to that of a normal knee, the medial soft tissue needed to be balanced more tightly than the lateral soft tissue during TKA. These findings provide some clinical evidence of TKA design selection and proper mediolateral balancing for successful TKA.

Finite element analysis of malposition in bi-unicompartmental knee arthroplasty.

Bi-unicompartmental knee arthroplasty is a less invasive treatment than a total one, great advantage for the patient but more difficult for the surgeon because of the lower visibility during surgery; this can therefore lead to eventual small errors in cutting angles during the procedure. The aim of this study is to investigate the effects of these slight angle variations in terms of anterior-posterior slope for the lateral tibial tray. The geometries of the bones were acquired and uncemented fixed bearing metal-back UKAs virtually implanted in a finite elements environment. The lateral component was implanted in six different antero-posterior slope configurations (from -5° to + 5° respect to medial component). Material properties for implant, bones and soft tissues were taken from the literature. A vertical compressive force of 2000N was applied in full-extended configuration on the femur. Von Mises stress distribution in proximal tibia, load/pressure/contact area repartitions between the medial and lateral compartments was extracted as outputs. Outcomes for 0° and -3° configurations are acceptable, but the -2° of slope configuration achieved the best ones in terms of stress on proximal tibia, load repartition, contact pressure distribution and shear component. Drastically different results are found for the ± 5° configurations, presenting a level of unbalancing often associated with weak stability and failure over time. Slight errors can happen during the surgery: performing the cut aiming to slightly posterior slopes during the surgery helps to minimize the chances of obtaining positive slopes that could lead to an unstable implant.

Registration of Bony Landmarks and Soft Tissue Laxity during Robotic Total Knee Arthroplasty is Highly Reproducible.

There is growing interest and enthusiasm for robotic total knee arthroplasty (TKA). Many robotic systems require registration of bony landmarks as well as a dynamic soft tissue evaluation to plan femoral and tibial resections. Variability in this user-driven registration can introduce error and undermine the purported precision and accuracy offered by robotics. The purpose of this study was to evaluate inter- and intrarater reliability in robotic registration with a new robotic system (ROSA®; Zimmer-Biomet, Warsaw, IN). Two unpaired cadaveric knee specimens were exposed, and optical arrays were placed into the femur and tibia. Three separate evaluators conducted repeated trials of anatomic registration and assessment of soft tissue laxity, as well as coronal alignment, sagittal alignment, femoral size, and maximum opening in the medial and lateral compartments in both flexion and extension. Repeated trials were conducted using these specimens with and without preoperative imaging for landmarking (image-based and image-free workflows). An Intraclass Correlation Coefficient (ICC) was calculated for each observer and across observers to determine intra-and interrater reliability, respectively, in robotic registration. There was good to excellent reliability for all conditions, and all correlation coefficients were >0.767. On average, ICCs for intrarater reliability were excellent for Doctor 1 (0.952), Doctor 2 (0.975), and Doctor 3 (0.925). On average, the ICCs for interrater reliability were excellent for both the "Registration + Gap Assessment" condition (0.961) and the "Gap Assessment" condition (0.994). Our results show a high repeatability of registration of anatomic landmarks and gap assessment among observers using this robotic system for both image-based and image-free software.

Understanding the Philosophy, Anatomy, and Surgery of the Extra-TME Plane of Locally Advanced and Locally Recurrent Rectal Cancer; Single Institution Experience with International Benchmarking.

Simple SummaryWorldwide there is still unwarranted variation in peri-operative management and subsequently oncological outcome following pelvic exenteration for locally advanced and recurrent rectal cancer. The major contributing factor seems to be a difference in treatment strategy with many centres aiming for more neoadjuvant treatment and less radical surgery. However, a radical resection with clear operative margins remains the single most important prognostic factor for survival and therefore an aggressive, radical approach is justified for an optimal oncological outcome and remains the gold standard of care.Pelvic exenteration surgery has become a widely accepted procedure for treatment of locally advanced (LARC) and locally recurrent rectal cancer (LRRC). However, there is still unwarranted variation in peri-operative management and subsequently oncological outcome after this procedure. In this article we will elaborate on the various reasons for the observed differences based on benchmarking results of our own data to the data from the PelvEx collaborative as well as findings from 2 other benchmarking studies. Our main observation was a significant difference in extent of resection between exenteration units, with our unit performing more complete soft tissue exenterations, sacrectomies and extended lateral compartment resections than most other units, resulting in a higher R0 rate and longer overall survival. Secondly, current literature shows there is a tendency to use more neoadjuvant treatment such as re-irradiation and total neoadjuvant treatment and perform less radical surgery. However, peri-operative chemotherapy or radiotherapy should not be a substitute for adequate radical surgery and an R0 resection remains the gold standard. Finally, we describe our experiences with standardizing our surgical approaches to the various compartments and the achieved oncological and functional outcomes.

Feasibility of transoral robotic selective neck dissection with or without a postauricular incision for papillary thyroid carcinoma: A pilot study.

BackgroundThe study aimed to evaluate the feasibility of transoral robotic selective neck dissection (SND) with or without a postauricular incision for papillary thyroid carcinoma (PTC).MethodsWe studied 14 patients with PTC who underwent robotic SND via the transoral or combined transoral and postauricular approaches.ResultsThe transoral approach was performed on 10 patients for dissection of levels III and IV. An additional postauricular incision was made on 4 patients for dissection of level II in addition to levels III, IV, and V. The operation was completed successfully in 13 patients, except 1 patient with the procedure conversion due to uncontrolled bleeding from the internal jugular vein. The mean numbers of removed lymph nodes in the lateral compartment were 23.1 ± 9.4 and 38.3 ± 8.5 in the transoral and combined groups. Transient recurrent laryngeal nerve palsy occurred in 1 patient, transient hypoparathyroidism in 3 patients, and chyle leakage in 1 patient. There were no hematomas, mental nerve injuries, surgical space infections, or CO2 embolisms.ConclusionTransoral robotic SND is feasible with or without a postauricular incision.

How does asymmetric tibial insert affect tibiofemoral kinematics and contact stresses in total knee Arthroplasty?

BackgroundAsymmetric tibial insert design is expected to restore normal knee kinematics better than symmetric design. A tri-condylar implant has asymmetric and symmetric tibial inserts with a ball-and-socket joint to replace the post-cam mechanism. The purpose of this study was to compare the knee kinematics of the two designs and to measure tibiofemoral contact stresses, including that of the ball-and-socket joint. MethodsUsing a computer simulation, the anteroposterior position and axial rotation of the femoral component were simulated during a weight-bearing deep knee bend for six validated models. Contact forces were simultaneously simulated in the medial, lateral, and ball-and-socket compartments. The relative position and the magnitude and direction of each contact force were applied to aforce/displacement control knee simulator. The contact stresses were measured individually using a pressure sensor. ResultsThe asymmetric tibial insert demonstrated a more posterior position of the femoral component in the lateral compartment during the entire range of motion and greater external rotation of the femoral component, compared to the symmetrical tibial insert. The mean peak contact stress of the medial and lateral compartments was < 9 Mpa, with no significant differences between the two designs except at 0°. The contact stress of the ball-and-socket joint was < 5 MPa. ConclusionsAsymmetry of the tibial insert shows significant kinematic difference and has little influence on the peak contact stress, which is considerably lower than the yield strength of polyethylene. The asymmetric tibial insert can lead to clinical benefits owing to its kinematic and kinetic properties.

Transtibial Repair of Lateral Meniscus Posterior Root Tears Improves Contact Biomechanics in Pediatric Cadavers

A paucity of data exists on the treatment of pediatric lateral meniscus root tears (LMPRTs). This study aims to characterize the biomechanics of the lateral knee joint in pediatric cadavers following LMPRT and root repair. Our hypotheses were: (1) compared with the intact state, LMPRT would be associated with decreased contact area; (2) compared with the intact state, LMPRT would be associated with increased contact pressures; and (3) compared with LMPRT, root repair would restore contact area and pressures toward intact meniscus values. Eight cadaver knees (ages 8-12 years) underwent contact area and pressure testing of the lateral compartment. Tekscan pressure mapping sensors covering the tibial plateau were inserted underneath the lateral meniscus. Appropriate pressure load equivalents were applied by a robot at degrees of flexion: 0, 30, 60. Three meniscus conditions were tested: (1) intact, (2) complete root tear, and (3) repaired root tear. Root repairs were performed with transtibial pullout sutures. Statistical analysis was performed. Root tear significantly decreased mean contact area at 30° (P= .0279) and 60° (P= .0397). Root repair increased mean contact area and did not significantly differ from intact states. Differences in contact pressures between meniscus states were not statistically significant. Relative to the intact state. the greatest increase in contact pressures occurred between 0° and 30°. Root repair decreased mean contact pressures at 0° and 30°. At 60°, mean contact pressures of the repair state were closer in magnitude to the tear state than the intact state. Conclusions: LMPRT decreases contact area and increases contact pressures in the lateral knee compartment. Repair of LMPRT improves tibiofemoral contact area at high (>30°) degrees of flexion and contact pressures at low (<30°) degrees of flexion. Transosseous pullout repair is a clinically validated treatment for LMPRT. This study provides baseline biomechanics data of transtibial pullout repair of pediatric LMPRTs.

Chronic Exertional Compartment Syndrome of the Lower Extremity: Diagnosis and Surgical Treatment.

Chronic exertional compartment syndrome of the lower extremity is a condition that characteristically presents as recurrent anterior, posterior, and/or lateral lower-extremity pain on repetitive activity and physical exertion1. This condition is commonly seen in athletes, runners, and military personnel2. Open fasciotomy has been demonstrated to be a highly effective surgical treatment for patients with this condition who do not experience symptomatic relief after a thorough trial of nonoperative treatment3. Diagnostic compartment pressure management is achieved through direct insertion of a compartment-pressure-measuring device into the anterior, lateral, and posterior compartments of the lower extremity4. Surgical treatment of the anterior and lateral compartments with use of open fasciotomy employs longitudinal proximal and distal incisions that are made on the lateral surface of the leg approximately 3 finger-breadths distal and proximal to the fibular flare, respectively, and 3 finger-breadths lateral to the tibial crest. Surgical treatment of the posterior compartments with use of open fasciotomy employs a single, mid-shaft incision made approximately 2.5 cm medial to the tibial ridge. Dissection is carried down to the deep fascia at both sites, beginning at the distal operative site. Care is taken to avoid transection of the superficial peroneal nerve at the distal anterolateral incision and saphenous vein and nerve at the medial incision. Once down to the deep fascia, a scalpel is utilized to incise the fascia. Metzenbaum scissors are then employed under the incision, spreading the scissors while sliding them over the muscles proximally and distally to release the muscular attachments from the fascia as well as to release the fascia itself3. This process is repeated in the anterior, lateral, and superficial posterior compartments through the proximal and distal incisions. In the deep posterior compartment, the fascia is released from the tibial ridge with a large Cobb elevator. Closure is achieved with deep dermal and superficial sutures. Nonoperative alternatives have been reported to include nonpharmacological modalities such as walking modification and shoe inserts, pharmacological therapy with nonsteroidal anti-inflammatory drugs, and physical therapy targeted at conditioning the lower extremity5. Nonoperative intervention has been demonstrated to increase endurance in select patients; however, most patients must either stop the activity associated with the compartment syndrome altogether or proceed to surgery for complete resolution of symptoms5. There are a few surgical alternatives that differ in their utilization of minimally invasive approaches versus a direct open approach6; however, all existing surgical treatments of this condition involve physical release of the fascial compartment. Diagnostic compartment-pressure measurement is useful in confirming or ruling out the presence of this condition in patients with unclear symptoms4. Furthermore, diagnostic compartment-pressure management ensures accuracy in diagnosis and validates invasive treatment when patients desire surgical intervention. Surgical management of exertional compartment syndrome of the lower extremity is indicated in patients when nonoperative treatment has failed despite clinically notable symptoms and objectively elevated lower-extremity compartment pressures. Open fasciotomy has been postulated to prevent compression of local vasculature and effectively prevent ischemia; however, the definitive mechanism is unclear1. Surgical treatment of chronic exertional compartment syndrome with use of open fasciotomy is highly successful in the civilian population. One study showed excellent return to activity/sport in 15 of 16 patients (25 of 26 limbs; 96%), with patients often reporting no symptoms postoperatively3. Military personnel have been reported to experience satisfactory results, with another study showing positive subjective feedback in 35 (76%) of 46 patients on long-term follow-up; however, only 19 patients (41%) were able to return to full active duty postoperatively7. Balloting the fascial compartment with ∼1 cc of saline solution can be helpful in determining successful placement of the pressure-measuring device at the time of needle entry.Identifying the course of the superficial peroneal nerve via physical examination can help avoid iatrogenic injury to this important superficial structure during the dissection leading to the distal fasciotomy.Deep posterior compartment release with use of open fasciotomy may not provide symptomatic relief; patients who demonstrate elevation of pressures in this specific compartment should be counseled accordingly. ROM = range of motionSPN = superficial peroneal nerve.

Lateral Joint Distraction Through Distal Fibula Lengthening Osteotomy for Lateral Compartment Ankle Osteoarthritis

Category: Ankle; Trauma Introduction/Purpose: Lateral compartment ankle OA, commonly due to trauma such as ankle fracture, is not very rare. However there's no definite established surgical treatment option. In this study, we suggest distal fibula lengthening osteotomy for lateral joint distraction as one of treatment surgical option. We have experienced favorable clinical outcome for 3 cases of post- traumatic lateral compartment ankle OA with joint space narrowing treated with distal fibula distraction osteotomy. We report the case series with the surgical technique and the clinical-radiological outcome. Methods: From April 2016 to August 2021, three ankles which underwent distal fibula distraction osteotomy were included in this study. All three ankles had a history of OR/IF due to fractures in the ankle joint and were diagnosed with lateral compartment OA. We defined lateral compartment OA when clinical symptoms and radiologic findings were consistent. Clinically, the point of pain was characterized as the lateral compartment of the ankle joint, not the syndesmosis or peri fibular area. Radiologically, joint space narrowing is showed in X-ray, and CT arthrography or MRI confirmed cartilage denudation of the lateral compartment. Results: 1) Clinical outcomes (Table 1) Case 1: The AOFAS score improved from 69 preoperatively to 93 postoperatively, and the Pain vas score improved from 7 to 0. According to patient's subjective expression, daily activity became 'Boxing available' from 'Hard to run'. Case 2: The AOFAS score improved from 73 preoperatively to 91 postoperatively, and the Pain vas score improved from 5 to 0. According to patient's subjective expression, daily activity became 'No pain on daily activity' from 'Hard to walk'. Case 3 is not described because there has been no progress for more than 1 year after surgery. 2) Radiologic outcomes (Table 2) Lateral joint space, talocrural angle, talar tilt angle and tibia axis-talar dome angle were all changed close to the contralateral ankle index after surgery. Conclusion: Painful ankle OA localized to the lateral compartment in young age is uncommon and there is no definite surgical method. Distal fibula distraction osteotomy is reasonable surgical method that does not burden patients and surgeon. In our study, distal fibula distraction osteotomy showed favorable clinical-radiological outcomes. So, we recommend this method for painful lateral compartment OA in young ages.

Posteromedial Tibial Bone Bruise After Anterior Cruciate Ligament Injury: An MRI Study of Bone Bruise Patterns in 208 Patients.

Background:Bone bruise patterns after anterior cruciate ligament (ACL) rupture may predict the presence of intra-articular pathology and help explain the mechanism of injury. Lateral femoral condyle (LFC) and lateral tibial plateau (LTP) bone bruises are pathognomic to ACL rupture. There is a lack of information regarding medial tibial plateau (MTP) and medial femoral condyle (MFC) bone bruises.Purpose:To summarize the prevalence and location of MTP bone bruises with acute ACL rupture and to determine the predictors of MTP bone bruises.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Inclusion criteria were patients who underwent ACL reconstruction between February 2015 and November 2017, magnetic resonance imaging (MRI) within 90 days of injury, and participation in the database. Exclusion criteria included previous ipsilateral surgery, multiligamentous injuries, and incomplete imaging. Due to the large number of cases remaining (n = 600), 150 patients were selected randomly from each year included in the study, for a total of 300 patients. Two readers independently reviewed injury MRI scans using the Costa-Paz bone bruise grading system. Logistic regression was used to identify factors associated with MTP bone bruises.Results:Included were 208 patients (mean age, 23.8 years; mean body mass index, 25.6). The mechanism of injury was noncontact in 59% of injuries, with over half from soccer, basketball, and football. The median time from injury to MRI scan was 12 days. Of the 208 patients, 98% (203/208) had a bone bruise, 79% (164/208) had an MTP bone bruise, and 83% (172/208) had bruises in both medial and lateral compartments. The most common pattern, representing 46.6% of patients (97/208), was a bruise in all 4 locations (MFC, LFC, MTP, and LTP). Of the 164 MTP bruises, 160 (98%) involved the posterior third of the plateau, and 161 were grade 1. The presence of an MFC bruise was the only independent risk factor for an MTP bruise (odds ratio, 3.71). The resulting nomogram demonstrated MFC bruise, sport, and mechanism of injury were the most important predictors of an MTP bruise.Conclusion:MTP bruise after acute ACL rupture was as prevalent as lateral bruises. The presence of a posterior MTP bruise suggested anterior tibial translation at the time of injury and could portend more medial compartment pathology at the time of injury than previously recognized.

Nomograms for the prediction of lateral lymph node metastasis in papillary thyroid carcinoma: Stratification by size

BackgroundLateral lymph node metastasis (LLNM) is a risk factor of poor prognosis in papillary thyroid cancer (PTC). We aimed to determine predictive factors and develop the nomograms for LLNM in patients with papillary thyroid microcarcinoma (PTMC) and macro-PTC.MethodsWe reviewed the medical records of 1,106 patients who underwent surgery between January 2019 and January 2022. Patients were divided into a PTMC and a macro-PTC group. We developed preoperative and postoperative nomograms for predicting LLNM based on results of multivariate analysis. Internal calibration was performed for these models.ResultsThe number of metastatic lymph nodes in lateral compartment was higher in macro-PTC patients. LLNM was independently associated with gender, the number of foci, location, shape, and central lymph node metastasis (CLNM) in PTMC patients. For macro-PTC patients, chronic lymphocytic thyroiditis, the number of foci, location, margin, CLNM, and central lymph node ratio were all independent predictors for LLNM. All the above factors were incorporated into nomograms, which showed the perfect discriminative ability.ConclusionThe diameter of the tumor has an impact on the rate of LLNM. Separate predictive systems should be used for PTMC and macro-PTC patients for more accurate clinical assessment of lateral lymph node status. Through these nomograms, we can not only detect high-risk patients with occult LLNM preoperatively, but also form appropriate treatment protocols for postoperative management of PTC patients with different risks.